It would really be powerful if Evernote could use Artificial Intelligence/Machine Learning to make notebook and tagging suggestions based on how previous notes have been placed (notebook wise) and tagged. An example process would be:
New document scanned
Evernote recommends, based on the contents of the newly scanned document and similar documents that have been scanned in the past, a notebook and possible tags for that new note.
The user can then confirm/validate the recommended selection. Maybe, at some point, the user can select an option to just accept the smart recommendations automatically